Problem: $\begin{aligned}&\phantom{{\times}}4\\ \\ &\underline{\times9} \end{aligned}$
We can think of ${4} \times {9}$ as $4$ rows of $9$ circles. How many circles are there? ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${4}$ ${\color{#9A72AC}{1}}$ ${\color{#9A72AC}{2}}$ ${\color{#9A72AC}{3}}$ ${\color{#9A72AC}{4}}$ ${\color{#9A72AC}{5}}$ ${\color{#9A72AC}{6}}$ ${\color{#9A72AC}{7}}$ ${\color{#9A72AC}{8}}$ ${\color{#9A72AC}{9}}$ ${3}$ ${\color{#9A72AC}{10}}$ ${\color{#9A72AC}{11}}$ ${\color{#9A72AC}{12}}$ ${\color{#9A72AC}{13}}$ ${\color{#9A72AC}{14}}$ ${\color{#9A72AC}{15}}$ ${\color{#9A72AC}{16}}$ ${\color{#9A72AC}{17}}$ ${\color{#9A72AC}{18}}$ ${2}$ ${\color{#9A72AC}{19}}$ ${\color{#9A72AC}{20}}$ ${\color{#9A72AC}{21}}$ ${\color{#9A72AC}{22}}$ ${\color{#9A72AC}{23}}$ ${\color{#9A72AC}{24}}$ ${\color{#9A72AC}{25}}$ ${\color{#9A72AC}{26}}$ ${\color{#9A72AC}{27}}$ ${1}$ ${\color{#9A72AC}{28}}$ ${\color{#9A72AC}{29}}$ ${\color{#9A72AC}{30}}$ ${\color{#9A72AC}{31}}$ ${\color{#9A72AC}{32}}$ ${\color{#9A72AC}{33}}$ ${\color{#9A72AC}{34}}$ ${\color{#9A72AC}{35}}$ ${\color{#9A72AC}{36}}$ $\begin{aligned}&\phantom{{\times}}4\\ \\ &\underline{\times9}\\ \\ &~~C{36} \end{aligned}$